In non-volatile memory systems, a file system may control how data is stored and retrieved through interactions with a flash translation layer, which maps logical addresses for memory operations to physical addresses of a memory device. In certain embodiments, due to handling of data by the file system and the interaction of the file system with the flash translation layer, the flash translation layer may become unaware that an intermediate storage contains obsolete versions of data. Thus, the flash translation layer may relocate the obsolete versions of data into main memory.